Light-emitting device and electronic apparatus

ABSTRACT

A light-emitting device includes a data signal supply circuit, a first switching element including a first end electrically coupled to the data signal supply circuit, and a second end, a first capacitor electrically coupled to the second end of the first switching element and configured to hold an electric charge according to a gradation voltage, a second switching element including a first end electrically coupled to the second end of the first switching element, and a second end, a pixel circuit including a light-emitting element and a transistor, and a data line electrically coupled to the pixel circuit. The first capacitor is disposed to overlap the transistor in plan view.

The present application is based on, and claims priority from JPApplication Serial Number 2018-152212, filed on Aug. 13, 2018, thedisclosure of which is hereby incorporated by reference herein in itsentirety.

BACKGROUND 1. Technical Field

The present disclosure relates to a light-emitting device and anelectronic apparatus.

2. Related Art

In recent years, various types of light-emitting devices usinglight-emitting elements such as organic light emitting diodes have beenproposed. Hereinafter, an organic light emitting diode is referred to asan OLED (Organic Light Emitting Diode). In a light-emitting device ofthe related art, a pixel circuit including a light-emitting element anda drive transistor is provided corresponding to an intersection betweena scanning line and a data line. JP-A-2016-38425 discloses a drivecircuit suitable for driving a micro-sized pixel circuit.

In the technology disclosed in JP-A-2016-38425, a holding capacitorconfigured to hold a gradation voltage to be output to a data line isprovided in the drive circuit. Accordingly, the holding capacitor isdisposed in a portion other than a display region, where the pixelcircuit is disposed, in the light-emitting device.

However, in the technology disclosed in JP-A-2016-38425, since theholding capacitor is provided in the portion other than the displayregion, there has been an issue such as enlargement of the portion otherthan the display region.

SUMMARY

In order to solve the above-described problem, one aspect of alight-emitting device according to the present disclosure includes adata signal supply circuit, a first switching element including a firstend electrically coupled to the data signal supply circuit, and a secondend, a first capacitor electrically coupled to the second end of thefirst switching element and configured to hold an electric chargeaccording to a gradation voltage, a second switching element including afirst end electrically coupled to the second end of the first switchingelement, and a second end, a pixel circuit including a light-emittingelement and a transistor, and a data line electrically coupled to thepixel circuit. The transistor supplies a current to the light-emittingelement according to the gradation voltage supplied via the data line,and the first capacitor is disposed to overlap the transistor in planview.

Further, in order to solve the above-described problem, one aspect of alight-emitting device according to the present disclosure includes adata signal supply circuit, a first switching element including a firstend electrically coupled to the data signal supply circuit, and a secondend, a first capacitor electrically coupled to the second end of thefirst switching element, a second switching element including a firstend electrically coupled to the second end of the first switchingelement, and a second end, a second capacitor including a first endelectrically coupled to the second end of the second switching element,and a second end, a pixel circuit including a light-emitting element anda transistor, and a data line electrically coupled to the second end ofthe second capacitor and the pixel circuit. The first capacitor isdisposed to overlap the transistor in plan view.

Further, in order to solve the above-described problem, one aspect of alight-emitting device according to the present disclosure includes adata signal supply circuit, a first switching element including a firstend electrically coupled to the data signal supply circuit, and a secondend, a first capacitor electrically coupled to the second end of thefirst switching element, a second switching element including a firstend electrically coupled to the second end of the first switchingelement, and a second end, a pixel circuit including a light-emittingelement and a transistor, and a data line electrically coupled to thesecond end of the second switching element and the pixel circuit. Thefirst capacitor is disposed to overlap the transistor in plan view.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a configuration of alight-emitting device 1 according to an exemplary embodiment of thepresent disclosure.

FIG. 2 is a diagram illustrating an electrical configuration of thelight-emitting device 1.

FIG. 3 is a diagram illustrating a configuration example of a pixelcircuit 110, a switch unit SW, and a demultiplexer DM.

FIG. 4 is a partial cross-sectional view of a display panel 10.

FIG. 5 is a plan view illustrating an arrangement of transistors 121 to125 and a pixel capacitor 132.

FIG. 6 is a plan view illustrating an arrangement of a second metallayer M02 and a second wiring layer L02.

FIG. 7 is a plan view illustrating an arrangement of a first metal layerM01 and the second wiring layer L02.

FIG. 8 is a plan view illustrating an arrangement of the first metallayer M01 and a first wiring layer L01.

FIG. 9 is a view for explaining Modification Example (1).

FIG. 10 is view for explaining Modification Example (2).

FIG. 11 is a view for explaining Modification Example (2).

FIG. 12 is a view for explaining Modification Example (3).

FIG. 13 is a perspective view illustrating a head-mounted display 300according to the present disclosure.

FIG. 14 is a perspective view illustrating a personal computer 400according to the present disclosure.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, modes for carrying out the present disclosure will bedescribed with reference to accompanying drawings. However, in eachfigure, a size and a scale of each unit is different from the actualsize and the actual scale of each unit as appropriate. Moreover,exemplary embodiments described below are suitable specific examples ofthe present disclosure, and various technically preferable limitationsare applied, but the scope of the present disclosure is not limited tothese modes unless it is specifically described in the followingdescription to limit the present disclosure.

A. Exemplary Embodiment

FIG. 1 is a perspective view illustrating a configuration of alight-emitting device 1 according to an exemplary embodiment of thepresent disclosure. The light-emitting device 1 serves as a microdisplay configured to display an image in a head-mounted display, forexample.

As illustrated in FIG. 1, the light-emitting device 1 includes a displaypanel 10 and a control circuit 3 configured to control an operation ofthe display panel 10. The display panel 10 includes a plurality of pixelcircuits, and a drive circuit configured to drive the pixel circuits. Inthe exemplary embodiment, the plurality of pixel circuits and the drivecircuit provided in the display panel 10 are formed in a siliconsubstrate, and an OLED being an example of an electro-optical element isused in each of the pixel circuits. Moreover, for example, the displaypanel 10 is housed in a frame-shaped case 82 opened at a display unit,and is coupled with one end of a Flexible Printed Circuits (FPC)substrate 84. A control circuit 3 of a semiconductor chip is mounted onthe FPC substrate 84 by a Chip On Film (COF) method, and a plurality ofterminals 86 are provided to be coupled to an upper circuit (notillustrated).

FIG. 2 is a block diagram illustrating a configuration of thelight-emitting device 1 according to the exemplary embodiment. Asdescribed above, the light-emitting device 1 includes the display panel10 and the control circuit 3. To the control circuit 3, an image dataVideo, which is digital, is supplied from the upper circuit (notillustrated) synchronously with a synchronization signal. Here, theimage data Video means data defining a display gradation of a pixel ofan image to be displayed on the display panel 10, precisely, a displayunit 100 described below by, for example, 8 bits. Moreover, thesynchronization signal means a signal including a verticalsynchronization signal, a horizontal synchronization signal, and a dotclock signal.

The control circuit 3 generates various control signals, based on thesynchronization signal, and supplies the control signals to the displaypanel 10. Specifically, the control circuit 3 supplies control signalsCtr1, Ctr2, Gref, /Gini, Gcpl, /Gcpl, Sel(1), Sel(2), Sel(3), /Sel(1),/Sel(2), and/Sel(3) to the display panel 10. Each of the control signalsCtr1 and Ctr2 is a signal including a plurality of signals such as apulse signal, a clock signal, and an enable signal. The control signalGref is a control signal having positive logic, and the controlsignal/Gini is a control signal having negative logic. The controlsignal Gcpl is also a control signal having positive logic, and thecontrol signal /Gcpl is a control signal having negative logic having arelationship of logic inversion with the control signal Gcpl. Thecontrol signal/Sel(1) has a relationship of logic inversion with thecontrol signal Sel(1). Similarly, the control signal /Sel(2) has arelationship of logic inversion with the control signal Sel(2), and thecontrol signal/Sel(3) has a relationship of logic inversion with thecontrol signal Sel(3), respectively. Note that the control signalsSel(1), Sel(2), and Sel(3) are generally referred to as a control signalSel, and the control signals/Sel(1), /Sel(2), and/Sel(3) are generallyreferred to as a control signal/Sel. A voltage generating circuit 31receives supply of power from a power supply circuit (not illustrated),and supplies a reset potential Vorst, a reference potential Vref, aninitialization potential Vini, and the like to the display panel 10.Hereinafter, a configuration including the reference potential Vref, thecontrol signal Gref, a transistor 43, a feed line 62, the initializationpotential Vini, the control signal/Gini, a transistor 45, and a feedline 61 will be described below, but these may be omitted.

Further, the control circuit 3 generates an analog image signal Vid,based on the image data Video. Specifically, a lookup table associatinga potential indicated by the image signal Vid and brightness of theelectro-optical element provided in the display panel 10 is stored inthe control circuit 3. Then, the control circuit 3 generates the imagesignal Vid indicating the potential corresponding to the brightness ofthe electro-optical element defined by the image data Video withreference to the lookup table, and supplies the image signal Vid to thedisplay panel 10.

As illustrated in FIG. 2, the display panel 10 includes the display unit100 and a drive circuit configured to drive the display unit 100. In theexemplary embodiment, the drive circuit is divided into a scanning linedrive circuit 4 and a data line drive circuit 5, but these circuits maybe integrated into a single circuit to constitute the drive circuit. Asillustrated in FIG. 2, the display unit 100 includes pixel circuits 110arranged in a matrix pattern, and corresponding to pixels of an image tobe displayed. Although a detailed illustration is omitted in FIG. 2, thedisplay unit 100 is provided with M rows of scanning lines 12 extendingin a horizontal direction (X direction) in the figure, and is alsoprovided with (3N) columns of data lines 14 grouped into each set ofthree columns and extending in a vertical direction (Y direction) in thefigure. Each of the scanning lines 12 and each of the data lines 14 areprovided to maintain mutual electrical insulation. The pixel circuits110 are provided corresponding to intersections between the M rows ofscanning lines 12 and the (3N) columns of data lines 14. Thus, in theexemplary embodiment, the pixel circuits 110 are arranged in a matrixpattern including M rows vertically and (3N) columns horizontally.

Here, each of M and N is a natural number. In the matrix of the scanninglines 12 and the pixel circuits 110, in order to distinguish the rowsfrom each other, the rows may be referred as row 1, 2, 3, . . . , (M−1),and M in order from the top in the figure. Similarly, to distinguish thecolumns from each other in the matrix of the data lines 14 and the pixelcircuits 110, the columns may be referred as column 1, 2, 3, . . . ,(3N−1), and (3N) in order from the left in the figure. Here, togeneralize and describe a group of the data lines 14, when n representsany integer of 1 or greater, the data lines 14 of columns (3n−2),(3n−1), and (3n) belong to a group n, as counting from the left. Thethree pixel circuits 110 corresponding to the scanning line 12 of thesame row and three columns of the data lines 14 belonging to the samegroup respectively correspond to R, G, and B pixels, and these threepixels represent one dot of a color image to be displayed. That is, inthe exemplary embodiment, a color of one dot is represented with anadditive color mixture by light emission of the OLED corresponding toRGB.

Moreover, as illustrated in FIG. 2, the display unit 100 is providedwith (3N) columns of feed lines 16 extending along the data lines 14.Each of the (3N) columns of feed lines 16 is provided to extend in thevertical direction, and to maintain mutual electrical insulation witheach of the scanning lines 12. Each of the feed lines 16 is a fixedpotential line supplied with a predetermined reset potential Vorst incommon from the voltage generating circuit 31. To distinguish thecolumns of the feed lines 16 from each other, the columns are referredto as the feed lines 16 of columns 1, 2, 3, . . . , and (3N)sequentially from the left in the figure. Each of the feed lines 16 ofcolumns 1 to (3N) is provided corresponding to each of the data lines 14of columns 1 to (3N).

The scanning line drive circuit 4 generates scanning signals Gwr forselecting M rows of the scanning lines 12 in a single frame periodsequentially row by row, in accordance with the control signal Ctr1. InFIG. 2, the scanning signals Gwr supplied to the scanning lines 12 ofrows 1, 2, 3, . . . , and M are respectively denoted by Gwr(1), Gwr(2),Gwr(3), . . . , Gwr(M−1), and Gwr(M). Note that the scanning line drivecircuit 4 generates, in addition to the scanning signals Gwr(1) toGwr(M), various types of control signals synchronized with the scanningsignals Gwr for each row, and supplies the control signals to thedisplay unit 100, however, such an illustration is omitted in FIG. 2.The frame period refers to a period necessary for the light-emittingdevice 1 to display one cut of an image. For example, when the frequencyof the vertical synchronization signal included in the synchronizationsignal is 120 Hz, the period is 8.3 milliseconds of one cycle.

As illustrated in FIG. 2, the data line drive circuit 5 includes (3N)switch units SW corresponding to (3N) columns of the data lines 14,respectively in a one-to-one relationship, N demultiplexers DM eachprovided to each of three columns of the data lines 14 constituting eachgroup, and a data signal supply circuit 70.

The data signal supply circuit 70 generates data signals Vd(1), Vd(2), .. . , and Vd(N), based on the image signal Vid and the control signalCtr2 supplied from the control circuit 3. That is, the data signalsupply circuit 70 generates the data signals Vd(1), Vd(2), . . . , andVd(N), based on the image signal Vid obtained by time divisionmultiplexing the data signals Vd(1), Vd(2), . . . , and Vd(N). Then, thedata signal supply circuit 70 supplies the data signals Vd(1), Vd(2), .. . , and Vd(N) to the demultiplexers DM corresponding to groups 1, 2, .. . , and N, respectively.

A configuration of the pixel circuit 110, the switch unit SW, and thedemultiplexer DM will now be described with reference to FIG. 3. Togenerally indicate the rows in which the pixel circuits 110 arearranged, m represents any integer of 1 or greater and M or less. Sincethe pixel circuits 110 are the same as one another in terms of anelectrical configuration, here, the pixel circuit 110 of row m, andcolumn (3n) positioned at row m and positioned at column (3n) will bedescribed as an example. The pixel circuit 110 of row m is supplied withthe scanning signal Gwr(m) and the control signals Gcmp(m) and Gel(m)from the scanning line drive circuit 4.

As illustrated in FIG. 3, a display region 112 of the display unit 100is a region for displaying an image. The display region 112 is providedwith the pixel circuit 110, and the data line 14 configured to supply agradation voltage to the pixel circuit 110. In addition, the displayregion 112 is provided with the feed lines 16 and 17 and first wiring 15for each column along the data line 14. In FIG. 3, the pixel circuit 110of row m and column (3n) is denoted by “110(m, 3n)”, and the data line14 of column (3n) is denoted by “14(3n)”. In FIG. 3, as with the dataline 14, the first wiring 15 of column (3n) is denoted by “15(3n)”, thefeed line 16 of column (3n) is denoted by “16(3n)”, and the feed line 17of column (3n) is denoted by “17(3n)”. As illustrated in FIG. 3, boththe data line 14(3n) and the first wiring 15(3n) are coupled to theswitch unit SW, and the pixel circuit 110 is coupled to the data line14(3n). Note that, in FIG. 3, the switch unit SW coupled to the dataline 14(3n) is denoted by “SW(3n)”, and the demultiplexer DM coupled tothe switch unit SW(3n) is denoted by “DM(n)”. The pixel circuit 110(m,3n) includes a first transistor 121, a second transistor 122, a thirdtransistor 123, a fourth transistor 124, and a fifth transistor 125 eachbeing a P-channel MOS-type transistor, an OLED 130, and a pixelcapacitor 132. In the following, the first transistor 121, the secondtransistor 122, the third transistor 123, the fourth transistor 124, andthe fifth transistor 125 may generally be referred to as the“transistors 121 to 125”.

A gate of the second transistor 122 is electrically coupled to thescanning line 12 (the scanning line 12 of row m in the case of the pixelcircuit 110(m, 3n)). Moreover, one of a source and a drain of the secondtransistor 122 is electrically coupled to the data line 14(3n), and theother is electrically coupled to a gate of the first transistor 121 andone of the electrodes of the pixel capacitor 132. The second transistor122 functions as a switching transistor configured to control electricalcoupling between the gate of the first transistor 121 and the data line14(3n).

A source of the first transistor 121 is electrically coupled to a feedline 116. A potential Vel being the high-order side of the power sourcein the pixel circuit 110 is supplied to the feed line 116 from a powersupply circuit (not illustrated). The first transistor 121 functions asa drive transistor in which a current corresponding to the voltagebetween the gate and source flows to the OLED 130.

One of a source and a drain of the third transistor 123 is electricallycoupled to the data line 14(3n), and the other is electrically coupledto a drain of the first transistor 121. The control signal Gcmp(m) isprovided to a gate of the third transistor 123. The third transistor 123is a transistor configured to conduct electric current, via the dataline 14(3n) and the second transistor 122, between the gate and thedrain of the first transistor 121. That is, the third transistor 123functions as a switching transistor configured to control electricalcoupling between the gate and the drain of the first transistor 121.

A source of the fourth transistor 124 is electrically coupled to thedrain of the first transistor 121, and a drain of the fourth transistor124 is electrically coupled to an anode of the OLED 130. The controlsignal Gel(m) is provided to a gate of the fourth transistor 124. Thefourth transistor 124 functions as a switching transistor configured tocontrol electrical coupling between the drain of the first transistor121 and the anode of the OLED 130.

One of a source and a drain of the fifth transistor 125 is electricallycoupled to the feed line 16(3n), that is, to a fixed potential lineconfigured to supply the reset potential Vorst, and the other is coupledto the anode of the OLED 130. The control signal Gcmp(m) is supplied toa gate of the fifth transistor 125. The fifth transistor 125 functionsas a switching transistor configured to control electrical couplingbetween the feed line 16(3n) and the anode of the OLED 130.

In the exemplary embodiment, since the display panel 10 is formed on asilicon substrate, a substrate potential of each of the transistors 121to 125 is assumed to be the potential Vel. Moreover, the sources and thedrains of the transistors 121 to 125 as described above may be reversedin accordance with the channel types and potential relationships of thetransistors 121 to 125. Moreover, each of the transistors may be a thinfilm transistor or may be a field effect transistor.

In the pixel capacitor 132, one electrode is electrically coupled to thegate of the first transistor 121, and the other electrode iselectrically coupled to the feed line 116. Thus, the pixel capacitor 132functions as a storage capacitor configured to hold the voltage betweenthe gate and the source of the first transistor 121. Note that, as thepixel capacitor 132, a capacitor parasitic on the gate of the firsttransistor 121 may be used, and a capacitor formed by sandwiching aninsulating layer between mutually different conductive layers in asilicon substrate may be used.

An anode 130 a of the OLED 130 is a pixel electrode providedindividually for each pixel circuit 110. In contrast, a cathode of theOLED 130 is a common electrode 118 commonly provided across all of thepixel circuits 110, and is coupled to a feed line 63. A potential Vctbeing a fixed potential is supplied to the feed line 63. Here, thepotential Vct may be equivalent to an L level of each of the scanningsignal and the control signal being logic signals. The OLED 130 is anelement including a white organic electroluminescent (EL) layersandwiched between the anode 130 a of the OLED 130 and the cathodehaving optical transparency of the OLED 130 in the above-describedsilicon substrate. Then, a color filter corresponding to any of RGB issuperimposed on an emission side of the OLED 130. In this example, theemission side of the OLED 130 is a cathode side of the OLED. Note thatan optical distance between the two reflection layers disposed tosandwich the white organic EL layer may be adjusted to form a cavitystructure, and a wavelength of light emitted from the OLED 130 may beset. In this case, a color filter may or may not be provided.

When a current flows from the anode 130 a to the common electrode 118being the cathode of the OLED 130, holes injected from the anode 130 aand electrons injected from the cathode are recombined in the organic ELlayer to produce excitons, and white light is generated. The white lightgenerated at this time passes through the cathode on the side oppositeto the silicon substrate, and the white light is colored by using acolor filter, and is visually recognized on the observer side.

As illustrated in FIG. 3, the demultiplexer DM(n) is an assembly of atransmission gate 34 and a capacitor 41 provided for each column, andsequentially supplies data signals to the three columns constitutingeach group. Input ends of the transmission gates 34 corresponding tocolumns (3n−2), (3n−1), and 3(n) belonging to group n are mutuallycoupled in common and the data signal Vd(n) is supplied to each of thecommon terminals. An output end of the transmission gate 34corresponding to column (3n) is coupled to an input end of the switchunit SW(3n) via a signal line 18(3n). While a detailed illustration isomitted in FIG. 3, an output end of the transmission gate 34corresponding to column (3n−1) is coupled to an input end of the switchunit SW(3n−1) via a signal line 18(3n−1), and an output end of thetransmission gate 34 corresponding to column (3n−2) is coupled to aninput end of the switch unit SW(3n−2) via a signal line 18(3n−2).

One electrode of the capacitor 41 corresponding to column (3n) iscoupled to the signal line 18(3n), and the other electrode of thecapacitor 41 corresponding to column (3n) is coupled to a feed line 64.Similarly, one electrode of the capacitor 41 corresponding to column(3n−1) is coupled to the signal line 18(3n−1), and one electrode of thecapacitor 41 corresponding to column (3n−2) is coupled to the signalline 18(3n−2). The other electrode of the capacitor 41 corresponding tocolumn (3n−1) and the other electrode of the capacitor 41 correspondingto column (3n−2) are coupled to the feed line 64. A potential VSS beinga fixed potential is supplied to the feed line 64. Here, the potentialVSS may be equivalent to the L level of each of the scanning signal andthe control signal being logic signals.

The transmission gate 34 provided in column (3n−2) being a left endcolumn in group n is turned on (conducts electricity) when the controlsignal Sel(1) is at an H level (when the control signal/Sel(1) is at theL level). Similarly, the transmission gate 34 provided in column (3n−1)being a center column in group n is turned on when the control signalSel(2) is at the H level (when the control signal/Sel(2) is at the Llevel), and the transmission gate 34 provided in column (3n) being aright end column in group n is turned on when the control signal Sel(3)is at the H level, that is, when the control signal/Sel(3) is at the Llevel.

The switch unit SW(3n) includes a transmission gate 42, an N-channel MOStype transistor 43, and a P-channel MOS type transistor 45. In theswitch unit SW(3n), an input end of the transmission gate 42 serves asan input end of the switch unit SW(3n). The signal line 18(3n) iscoupled to the input end of the transmission gate 42 of the switch unitSW(3n). The first wiring 15(3n) is coupled to a node h in the signalline 18(3n). Accordingly, in the demultiplexer DM(n), one of theelectrodes of the capacitor 41 corresponding to column 3n is coupled tothe first wiring 15(3n) via the signal line 18(3n). The data line 14(3n)is coupled to an output end of the transmission gate 42. The controlsignal Gcpl and the control signal/Gcpl are supplied from the controlcircuit 3 to the transmission gate 42. The transmission gate 42 isturned on when the control signal Gcpl is at the H level, that is, whenthe control signal/Gcpl is at the L level. When the transmission gate 42is turned on, the first wiring 15(3n) coupled to the signal line 18(3n)is electrically coupled to the data line 14(3n) in the signal line18(3n) and the node h.

A drain of the transistor 45 is coupled to the data line 14(3n), and asource of the transistor 45 is coupled to the feed line 61 to which apredetermined initialization potential Vini is supplied. The controlcircuit 3 supplies the control signal/Gini to a gate of the transistor45. In the transistor 45, the data line 14(3n) and the feed line 61 areelectrically coupled to each other when the control signal/Gini is atthe L level, and are electrically uncoupled when the control signal/Gini is at the H level. When the data line 14(3n) is electricallycoupled to the feed line 61, a potential of the data line 14(3n) becomesthe initialization potential Vini.

A drain of the transistor 43 is coupled to the data line 14(3n), and asource of the transistor 43 is coupled to the feed line 62 to which thereference potential Vref is supplied. The reference potential Vref is areference potential used in a compensation operation of compensating athreshold voltage of the drive transistor, that is, the first transistor121 of the pixel circuit 110. The control signal Gref is supplied to agate of the transistor 43. In the transistor 43, the data line 14(3n)and the feed line 62 are electrically coupled to each other when thecontrol signal Gref is at the H level, and are electrically uncoupledwhen the control signal Gref is at the L level. When the data line14(3n) is electrically coupled to the feed line 62, a potential of thedata line 14(3n) becomes the reference potential Vref.

A capacitor 44 in FIG. 3 is an inter-wiring capacitor formed between thefeed line 16 and the first wiring 15(3n). A capacitor 40 in FIG. 3 is aninter-wiring capacitor formed between the feed line 17 and the firstwiring 15(3n). The feed line 17 is provided with the potential Vel. Whenthe transmission gate 34 is turned on in a state where the transmissiongate 42 is turned off, a data signal Vd(n) is supplied to the signalline 18(3n) from the output end of the transmission gate 34, and acharge commensurate with a gradation voltage indicated by the datasignal Vd(n) is accumulated in the capacitors 40, 41, and 44. That is,the capacitors 40, 41, and 44 of column (3n) each serve as a holdingcapacitor configured to hold a gradation voltage commensurate with adisplay gradation of the pixel circuit 110 of column (3n). Then, whenthe transmission gate 42 is turned on in a state where the gradationvoltage is held in the capacitors 40, 41, and 44, the signal line 18(3n)and the first wiring 15(3n) are electrically coupled to the data line14, and the gradation voltage held in the capacitors 40, 41, and 44 issupplied to the pixel circuit 110(m, 3n) via the data line 14(3n).

In the exemplary embodiment, the capacitor 41 is provided together withthe transmission gate 34, the transmission gate 42, and the transistors43 and 45 in a portion other than the display region 112, that is, anouter frame region surrounding the display region 112 in thelight-emitting device 1. On the other hand, the capacitors 40 and 44 areprovided in the display region (that is, the display region 112). Asdescribed above, the capacitor 44 of column (3n) is an inter-wiringcapacitor formed between the feed line 16(3n) and the first wiring15(3n), and the feed line 16(3n) and the first wiring 15(3n) areprovided side by side in the display region 112 to form the capacitor44. Further, the capacitor 40 of column (3n) is an inter-wiringcapacitor formed between the feed line 17(3n) and the first wiring15(3n), and the first wiring 15(3n) is provided with an electrode 40 athat faces the feed line 17(3n) in the display region 112 to form thecapacitor 40. Further, in a case where the electrode 40 a includes aportion facing the feed line 16(3n), the capacitor 44 in column (3n) isalso formed between the electrode 40 a and the feed line 16(3n).

FIG. 4 is a partial cross-sectional view illustrating a cross section ofthe display unit 100 in a plane passing through the pixel circuits110(m, 3n−2), 110(m, 3n−1), and 110(m, 3n). As illustrated in FIG. 4,the display unit 100 includes a circuit layer C01, a second metal layerM02, a second wiring layer L02, a first metal layer M01, a first wiringlayer L01, a reflective layer R01, an insulating layer ISO, alight-emitting element layer OL, a first sealing layer S01, aplanarization layer A01, a second sealing layer S02, a color filterlayer F, and a transparent substrate 101 layered one on another in thisorder.

The transparent substrate T01 is formed of glass or a transparent resin.The color filter layer F is provided with the above-described colorfilter. The first sealing layer S01 and the second sealing layer S02 areeach formed of SiO_(n) by a film formation method such as chemical vapordeposition (CVD), for example. The planarization layer A01 is formed ofan epoxy resin by a film formation method such as printing and anink-jet method, for example. In the light-emitting element layer OL, theOLED 130 described above is formed. FIG. 4 illustrates the commonelectrode 118 being the cathode and the anode 130 a of the OLED 130. Inthe circuit layer C01, the transistors 121 to 125 and the pixelcapacitor 132 included in the pixel circuit 110 are formed. In theexample illustrated in FIG. 4, the pixel capacitor 132 and thetransistor 121, more precisely, the gate of the transistor 121, areillustrated as an example of a circuit element formed in the circuitlayer C01. Here, the circuit layer C01 includes a metal layer MG, andthe pixel capacitor 132 includes an electrode 132 a that forms acapacitor between the metal layer MG and the electrode 132 a. The metallayer MG and the electrode 132 a are each formed of a metal such asaluminum by a film formation method such as CVD, for example. Note that,in the circuit layer C01, an interlayer insulating film or a dielectricfilm formed of SiO₂, SiN, or the like is appropriately disposed betweenconductor layers such as the metal layer MG and the electrode 132 a.

The second metal layer M02, the second wiring layer L02, the first metallayer M01, and the first wiring layer L01 are each formed of a metalsuch as aluminum by a film formation method such as CVD, for example. Aninterlayer insulating film or a dielectric film formed of SiO₂, SiN, orthe like is appropriately disposed between these layers. As illustratedin FIG. 4, the first metal layer M01 is provided closer to thelight-emitting element layer OL side than the circuit layer C01, and thefirst wiring layer L01 is provided closer to the light-emitting elementlayer OL side than the first metal layer M01. As illustrated in FIG. 4,the feed line 16(3n) and the first wiring 15(3n) are formed in the firstwiring layer L01. Since the capacitor 44 of column (3n) is aninter-wiring capacitor formed between the feed line 16(3n) and the firstwiring 15(3n) as described above, the capacitor 44 is formed in thefirst wiring layer L01.

The second metal layer M02 and the second wiring layer L02 are formedbetween the circuit layer C01 and the first metal layer M01, and thedata line 14(3n) and second wiring 20(3n) are formed in the secondwiring layer L02. Moreover, the first metal layer M01 and the secondmetal layer M02 are coupled to each other via a plurality of wiringportions 19. The wiring portion 19 includes a relay metal layer 19 a, aplurality of contact portions 19 b, and a plurality of contact portions19 c. The plurality of contact portions 19 b couple the first metallayer M01 to the relay metal layer 19 a. The plurality of contactportions 19 c couple the second metal layer M02 to the relay metal layer19 a. The relay metal layer 19 a is formed in the same layer as the dataline 14. In the exemplary embodiment, as illustrated in FIG. 4, the dataline 14 is surrounded by the first metal layer M01, the second metallayer M02, and the plurality of wiring portions 19 at the fixedpotential when viewed in cross section across the data line 14. Notethat the second wiring 20 in the exemplary embodiment is dummy wiring,and may be, for example, supplied with a fixed potential or omitted.

Here, the first metal layer M01, the second metal layer M02, and theplurality of wiring portions 19 are supplied with a common fixedpotential (the potential Vel in the exemplary embodiment) from the feedline 17, and the first metal layer M01, the second metal layer M02, andthe plurality of wiring portions 19 serve as a shield configured toprotect the data line 14(3n) from electrostatic noise. From a differentperspective, the first metal layer M01, the second metal layer M02, andthe plurality of wiring portions 19 function as the feed line 17.Further, the capacitor 40 of column (3n) is an inter-wiring capacitorbetween the feed line 17(3n) and the first wiring 15(3n), and thecapacitor 40 is formed between the electrode 40 a coupled to the firstwiring 15(3n) and the first metal layer M01.

As described above, the first wiring layer L01 in which the capacitors40 and 44 are formed and the first metal layer M01 are overlaid on thesecond wiring layer L02 in which the data line 14 to which the pixelcircuit 110 is coupled is formed, and thus the capacitors 40 and 44forming a holding capacitor together with the capacitor 41 are formed inthe display region 112. In the exemplary embodiment, since thecapacitors 40, 41, and 44 each serve as a holding capacitor configuredto hold the gradation voltage according to the display gradation of thepixel circuit 110, a size of the capacitor 41 can be reduced as comparedto an aspect in which the capacitors 40 and 44 are not provided, and anarea of the outer frame region of the display panel 10 can be reduced.Thus, according to the exemplary embodiment, a chip area of the portionother than the display region 112 in the light-emitting device 1 can bereduced.

In addition, the capacitor 40 overlaps the first transistor 121 in planview. Thus, the capacitor 40 serves not only as the holding capacitordescribed above, but also serves as an electrostatic shield and lightshielding for the first transistor 121.

FIG. 5 is a plan view illustrating an arrangement of the transistors 121to 125 and the pixel capacitor 132. As illustrated in FIG. 5, thecircuit layer C01 includes semiconductor layers SE1 and SE2, gateelectrodes G1, G2, G3, G4, and G5, and contact portions CP1, CP2, CP3,CP4, CP5, CP6, and CP7.

The semiconductor layer SE1 is provided corresponding to the firsttransistor 121. The gate electrode G1 corresponding to the firsttransistor 121 is disposed on the semiconductor layer SE1 via a gateinsulating film (not illustrated). Further, the contact portions CP1 andCP2 are coupled to the semiconductor layer SE1, and one of the contactportions CP1 and CP2 functions as a source electrode of the firsttransistor 121 and the other functions as a drain electrode of the firsttransistor 121. The contact portion CP1 is electrically coupled to thefeed line 116, and the contact portion CP2 is electrically coupled tothe third transistor 123 and the fourth transistor 124 via a portion MG2described later and the contact portion CP5.

The semiconductor layer SE2 is provided commonly to the secondtransistor 122, the third transistor 123, the fourth transistor 124, andthe fifth transistor 125. The gate electrodes G2, G3, G4, and G5 aredisposed on the semiconductor layer SE2 via a gate insulating film (notillustrated). The gate electrodes G2, G3, G4, and G5 correspond to thesecond transistor 122, the third transistor 123, the fourth transistor124, and the fifth transistor 125, respectively. In the illustration,the gate electrodes G3 and G5 are integrated. Further, the contactportions CP3, CP4, CP5, CP6, and CP7 are coupled to the semiconductorlayer SE2. One of the contact portions CP3 and CP4 functions as a sourceelectrode of the second transistor 122 and the other functions as adrain electrode of the second transistor 122. One of the contactportions CP4 and CP5 functions as a source electrode of the thirdtransistor 123 and the other functions as a drain electrode of the thirdtransistor 123. One of the contact portions CP5 and CP6 functions as asource electrode of the fourth transistor 124 and the other functions asa drain electrode of the fourth transistor 124. One of the contactportions CP6 and CP7 functions as a source electrode of the fifthtransistor 125 and the other functions as a drain electrode of the fifthtransistor 125. Therefore, one of the source electrode and the drainelectrode of the second transistor 122 is provided commonly to one ofthe source electrode and the drain electrode of the third transistor123, and this common portion is the contact portion CP4. Further, one ofthe source electrode and the drain electrode of the third transistor 123is provided commonly to one of the source electrode and the drainelectrode of the fourth transistor 124, and this common portion is thecontact portion CP5. Further, one of the source electrode and the drainelectrode of the fourth transistor 124 is provided commonly to one ofthe source electrode and the drain electrode of the fifth transistor125, and this common portion is the contact portion CP6.

The contact portion CP3 is electrically coupled to the gate electrode G1of the first transistor 121 via a portion MG1 described later and thecontact portion CP8. The contact portion CP4 is electrically coupled tothe data line 14. The contact portion CP5 is electrically coupled to thedrain of the first transistor 121. The contact portion CP6 iselectrically coupled to the anode of the OLED 130. The contact portionCP7 is electrically coupled to the feed line 16.

The gate electrode G2 is electrically coupled to the scanning line 12via the contact portion CP9. The gate electrodes G3 and G5 areelectrically coupled to a control line 21 via the contact portion CP11.The gate electrode G4 is electrically coupled to the control line 22 viathe contact portion CP10. The feed line 116 is electrically coupled to aportion M02 a described later via the contact portion CP12.

Further, the metal layer MG of the circuit layer C01 includes theportion MG1 that overlaps the first transistor 121 in plan view. Themetal layer MG also includes the portion MG2 that electrically couplesthe contact portion CP2 to the contact portion CP5. The electrode 132 afaces the portion MG1 to overlap the portion MG1 in plan view, and thepixel capacitor 132 described above is formed between the portion MG1and the electrode 132 a. As illustrated in FIG. 5, the capacitor 40,more specifically, the electrode 40 a of the capacitor 40 overlaps thefirst transistor 121 in plan view. In addition, the capacitor 40, morespecifically, the electrode 40 a of the capacitor 40 overlaps the pixelcapacitor 132, specifically, the electrode 132 a in plan view.

FIG. 6 is a plan view illustrating an arrangement of the second metallayer M02 and the second wiring layer L02. As illustrated in FIG. 6, thesecond metal layer M02 includes the portion M02 a that contains thecapacitor 40 in plan view. Although it is not illustrated in the figure,the portion M02 a forms a shape that overlaps the first transistor 121inplan view. Further, the second wiring layer L02 is formed on theportion M02 a. Specifically, a part of the data line 14 and a part ofthe second wiring 20 extend on the portion M02 a, and the two wiringportions 19 are disposed to sandwich the data line 14 and the secondwiring 20. As illustrated in FIG. 6, the plurality of contact portions19 c of each of the wiring portions 19 are aligned along the data line14. Further, the scanning line 12 and the control lines 21 and 22 areformed in the second metal layer M02. Further, the second wiring layerL02 includes a portion L02 a electrically coupled to the anode of theOLED 130 and a portion L02 b electrically coupled to the feed line 16.

FIG. 7 is a plan view illustrating an arrangement of the first metallayer M01 and the second wiring layer L02. FIG. 8 is a plan viewillustrating an arrangement of the first metal layer M01 and the firstwiring layer L01. As illustrated in FIG. 7, the relay metal layer 19 aof each of the wiring portions 19 has a shape extending along the dataline 14, and the plurality of contact portions 19 b are aligned alongthe data line 14 on the relay metal layer 19 a. As illustrated in FIGS.7 and 8, the first metal layer M01 has a shape that contains thecapacitor 40 in plan view. As illustrated in FIG. 8, the electrode 40 aof the capacitor 40 includes a portion that overlaps the first wiring 15in plan view. A contact portion 40 b coupled to the first wiring 15 isprovided on the portion of the electrode 40 a. Although it is notillustrated in the figure, the first metal layer M01 overlaps the firsttransistor 121 in plan view.

As described above, the light-emitting device 1 above includes the pixelcircuit 110 disposed in the display region 112, the data line 14 coupledto the pixel circuit 110, the data line drive circuit 5 configured tooutput the data signal Vd(N) to the data line 14, and the capacitor 40being a first capacitor configured to hold the data signal Vd(N). Here,the pixel circuit 110 includes the light-emitting element 130, and thefirst transistor 121 being a transistor configured to supply a currentbased on the data signal Vd(N) according to a gradation to be displayedto the light-emitting element 130. The capacitor 40 is disposed in thedisplay region 112 to overlap the first transistor 121 in plan view.

In this way, in the light-emitting device 1, the capacitor 40 thatserves as a holding capacitor configured to hold the data signal Vd(N)is provided in the display region 112. Thus, in the light-emittingdevice 1, an area of a portion other than the display region 112 in thelight-emitting device 1 can be reduced as compared to the related art inwhich a holding capacitor is provided only in a portion other than adisplay region.

In the light-emitting device 1, the capacitor 40 is disposed to overlapthe first transistor 121, serving as a drive transistor configured tosupply a current based on the data signal Vd(N) to the light-emittingelement 130, in plan view. Thus, in the light-emitting device 1, thecapacitor 40 also serves as an electrostatic shield and light shieldingfor the first transistor 121. In this way, since the capacitor 40simultaneously plays a plurality of roles, layout efficiency of thepixel circuit 110 is increased as compared to a case where thesefunctions are configured separately. As a result, fine pixels can beachieved.

As described above, the light-emitting device 1 further includes thecircuit layer C01 in which the pixel circuit 110 is provided, the firstwiring layer L01 in which the first wiring 15 disposed along the dataline 14 is provided, and the first metal layer M01 disposed between thecircuit layer C01 and the first wiring layer L01. Here, the potentialVel being a fixed potential is supplied to the first metal layer M01,and the first metal layer M01 includes a portion disposed between thedata line 14 and the first wiring 15. Thus, the first metal layer M01serves as an electrostatic shield between the data line 14 and the firstwiring 15. As a result, the generation of crosstalk between the dataline 14 and the first wiring 15 can be reduced, and the display qualitycan be improved.

As described above, the first metal layer M01 overlaps the firsttransistor 121 in plan view. Thus, the first metal layer M01 serves aslight shielding for the first transistor 121. Here, since the firstmetal layer M01 is a layer different from the first wiring layer L01,there is an advantage that an area of the portion of the first metallayer M01 that serves as light shielding can be easily increased ascompared to a case where the first metal layer M01 is the same layer asthe first wiring layer L01.

As described above, the capacitor 40 is a capacitor between theelectrode 40 a coupled to the first wiring 15 and the first metal layerM01. In this way, since the capacitor 40 is provided between the firstwiring 15 and the first metal layer M01, the capacitor 40 can serve aslight shielding for the first transistor 121 by using light-shieldingproperties of the first metal layer M01. Here, the first metal layer M01simultaneously serves as one of the pair of electrodes constituting thecapacitor 40. As a result, in the light-emitting device 1, the layoutefficiency of the pixel circuit 110 is increased as compared to a casewhere a holding capacitor is configured without using the first metallayer M01.

As described above, the light-emitting device 1 further includes thesecond metal layer M02 disposed between the circuit layer C01 and thefirst metal layer M01, and the second wiring layer L02 disposed betweenthe first metal layer M01 and the second metal layer M02. Here, a fixedpotential is supplied to the second metal layer M02. Then, the data line14 is provided in the second wiring layer L02 disposed between the firstmetal layer M01 and the second metal layer M02. Thus, the data line 14can be shielded electrostatically by the first metal layer and thesecond metal layer at the fixed potential.

The second metal layer M02 overlaps the first transistor 121 in planview. Thus, the second metal layer M02 serves as light shielding for thefirst transistor 121. Here, since the second metal layer M02 is a layerdifferent from the first wiring layer L01 and the data line 14, there isan advantage that an area of the portion of the second metal layer M02that serves as light shielding can be easily increased as compared to acase where the second metal layer M02 is the same layer as the firstwiring layer L01 or the data line 14.

As described above, the light-emitting device 1 further includes theplurality of wiring portions 19 configured to couple the first metallayer M01 to the second metal layer M02. Here, the data line 14 includesa portion disposed between a pair of wiring portions of the plurality ofwiring portions 19. Thus, the data line 14 can be shieldedelectrostatically by the plurality of wiring portions 19 at the fixedpotential.

As described above, the light-emitting device 1 further includes thefeed line 16 being a fixed potential line disposed along the data line14, and the capacitor 44 being a second capacitor configured to hold thedata signal Vd(N). Here, the reset potential Vorst being a fixedpotential is supplied to the feed line 16. Then, the capacitor 44 is acapacitor between the first wiring 15 and the feed line 16. In this way,not only the capacitor 40 but also the capacitor 44 serve as a holdingcapacitor configured to hold the data signal Vd(N). Thus, a holdingcapacitor in the display region 112 can be easily increased as comparedto a case where the capacitor 44 between the first wiring 15 and thefeed line 16 is not used. In addition, since the feed line 16 isdisposed along the data line 14 in the same manner as the first wiring15, the capacitor 44 is easily formed between the first wiring 15 andthe feed line 16 as compared to a case where the first wiring 15 and thefeed line 16 are disposed along different directions from each other.

Note that, in the exemplary embodiment, in addition to the capacitors 40and 44, the capacitor 41 serves as a holding capacitor configured tohold the data signal Vd(N), and at least one of the capacitors 41 and 44may be omitted. In this case, in particular, by omitting the capacitor41 disposed outside the display region 112, an area of a portion otherthan the display region 112 in the light-emitting device 1 can bereduced.

Further, one of the capacitors 40 and 44 may be omitted, and the othermay overlap a drive transistor in plan view. Further, the capacitor 44may overlap the first transistor 121 in plan view, and, in this case,the capacitor 40 may overlap or may not overlap the first transistor 121in plan view. The capacitor 44 is an inter-wiring capacitor between thefeed line 16 (3n) and the first wiring 15(3n), but at least a part ofthe feed line 16 (3n) and the first wiring 15(3n) or a part (a portionformed by the capacitor) between the feed line 16 (3n) and the firstwiring 15(3n) may overlap the first transistor 121 in plan view. In theabove description, a potential of the feed line 17 is the potential Vel,and a potential of the feed line 16 is the reset potential Vorst, butthese potentials may be another fixed potential. However, from aperspective of simplifying the circuit, a potential supplied to one ofthe electrodes of the capacitors 40 and 44 is preferably a potentialused in the pixel circuit 110.

As described above, the first wiring 15 and the feed line 16 areprovided in the same layer, that is, in the first wiring layer L01.Thus, as compared to a case where the first wiring 15 and the feed line16 are provided in different layers, the wiring can be efficientlydisposed. Here, since both of the first wiring 15 and the feed line 16are disposed along the data line 14, it is easy to provide these layersin the same layer.

As described above, the data line 14 is disposed between the firsttransistor 121 and the first wiring 15. Thus, a distance between thedata line 14 and the first wiring 15 can be easily increased as comparedto a case where the data line 14 and the first wiring 15 are provided inthe same layer. Further, a distance between the data line 14 and thepixel circuit 110 is shortened, and thus the wiring between the dataline 14 and the pixel circuit 110 is simplified.

B. Modification Example

Although an exemplary embodiment of the present disclosure is describedabove, the following modification examples may be added to thisexemplary embodiment.

(1) In the above exemplary embodiment, the second wiring layer L02provided with the data line 14(3n) is separately provided from the firstwiring layer L01 provided with the feed line 16(3n) and the first wiring15(3n). However, as illustrated in FIG. 9, a second wiring layer L02 anda second metal layer M02 may be omitted, and a feed line 16(3n), a dataline 14(3n), and first wiring 15(3n) may be provided in a first wiringlayer L01.

(2) As illustrated in FIG. 10, the data line 14(3n) in FIG. 3 may bedivided into a data line 14′(3n) to which a pixel circuit 110 and atransistor 45 are coupled, and second wiring 20′(3n) to which an outputend of a transmission gate 42 and a transistor 43 are coupled, and acapacitor 50 (second capacitor) may be provided between the data line14′(3n) and the second wiring 20′(3n). This enables the pixel circuit110 to perform coupling drive by using the capacitor 50 as a transfercapacitor. Moreover, the second wiring 20′(3n) may be provided in thesecond wiring layer L02 to extend along the data line 14′(3n) (see FIG.11), and an inter-wiring capacitor formed between the data line 14′(3n)and the second wiring 20′(3n) may serve as the capacitor 50. Thisenables the transfer capacitor used in the coupling drive to be providedin the display region 112 of a display unit 100, and enables the chiparea of the portion other than the display region 112 to be reduced ascompared to an aspect in which the transfer capacitor is provided in theportion other than the display region 112.

(3) As illustrated in FIG. 12, a data line 14′ in FIG. 10 may be dividedvertically into two portions of a data line 14′A provided from a firstrow to row m, and a data line 14′B provided from row (m+1) to row M, andthe second wiring 20′ may be divided vertically into two portions ofsecond wiring 20A coupled via a transmission gate 42A to the firstwiring 15 and second wiring 20B coupled via a transmission gate 42B tothe first wiring 15, as illustrated in FIG. 12. Note that a capacitor50A in FIG. 12 serves as an inter-wiring capacitor formed between thedata line 14′A and the second wiring 20A, and a capacitor 50B in FIG. 12serves as an inter-wiring capacitor formed between the data line 14′Band the second wiring 20B. Moreover, a transistor 43A in FIG. 12 servesas a transistor configured to switch coupling and decoupling between avoltage generating circuit 31 being a reference power supply configuredto supply a reference potential Vref and the second wiring 20A. Atransistor 43B serves as a transistor configured to switch coupling anddecoupling between the second wiring 20B and the above-describedreference power supply. A transistor 45A in FIG. 12 is a transistorconfigured to switch coupling and decoupling between the voltagegenerating circuit 31 being an initialization power supply configured tosupply an initialization potential Vini and the data line 14′A. Atransistor 45B is a transistor configured to switch coupling anddecoupling between the data line 14′B and the initialization powersupply.

In the aspect illustrated in FIG. 12, the transmission gate 42A and thetransmission gate 42B are switched on and off and thus, a pixel circuit110A coupled to the data line 14′A and a pixel circuit 110B coupled tothe data line 14′B can be driven independently and separately from eachother. For example, while the transmission gate 42A is turned on towrite a gradation voltage to the pixel circuit 110A, the transmissiongate 42B can be turned off and the transistor 43B can be turned on toperform a compensation operation of a threshold voltage for a drivetransistor of the pixel circuit 110B. Although a potential of the dataline 14′B varies while the compensation operation for the drivetransistor of the pixel circuit 110B is executed, the data line 14′A isdecoupled from the data line 14′B and thus, no trouble occurs in thewriting of the gradation voltage to the pixel circuit 110A. According tothe aspect illustrated in FIG. 12, during the writing of the gradationvoltage to one of the pixel circuit 110A and the pixel circuit 110B, thecompensation operation for the other can be initiated, and a period forexecuting the compensation operation (compensation period) can be longerthan in the related art. Generally, a compensating effect of thethreshold voltage increases as the compensation period becomes longer,and thus, according to the aspect illustrated in FIG. 12, thecompensation effect of the threshold voltage of the drive transistorprovided in the pixel circuit can be enhanced. Further, according to theaspect illustrated in FIG. 12, a size of the portion other than thedisplay region can be reduced.

C. Application Example

The light-emitting device according to the exemplary embodimentdescribed above can be applied to various electronic apparatuses, and isparticularly suitable for an electronic apparatus required to display ahigh-definition image of at least 2K by 2K and required to be compact.Hereinafter, an electronic apparatus according to the present disclosurewill be described.

FIG. 13 is a perspective view illustrating an outer appearance of ahead-mounted display 300 as an electronic apparatus employing thelight-emitting device of the present disclosure. As illustrated in FIG.13, the head-mounted display 300 includes a temple 310, a bridge 320, aprojection optical system 301L, and a projection optical system 301R.Then, in FIG. 13, a light-emitting device for a left eye (notillustrated) is provided behind the projection optical system 301L, anda light-emitting device for a right eye (not illustrated) is providedbehind the projection optical system 301R.

FIG. 14 is a perspective view illustrating a personal computer 400 of aportable type employing the light-emitting device 1 according to thepresent disclosure. The personal computer 400 includes thelight-emitting device 1 configured to display various images, and a mainbody portion 403 provided with a power switch 401 and a keyboard 402.Note that examples of the electronic apparatus to which thelight-emitting device 1 according to the present disclosure is appliedinclude, in addition to the apparatuses illustrated in FIG. 13 and FIG.14, an electronic apparatus disposed close to eyes such as a digitalscope, a digital binocular, a digital still camera, and a video camera.Further, the light-emitting device according to the present disclosurecan be applied as a display unit provided in an electronic apparatussuch as a mobile phone, a smartphone, a personal digital assistant(PDA), a car navigation device, and an automotive instrument panel.

What is claimed is:
 1. A light-emitting device comprising: a data signalsupply circuit; a first switching element including a first endelectrically coupled to the data signal supply circuit, and a secondend; a first capacitor electrically coupled to the second end of thefirst switching element and configured to hold an electric chargeaccording to a gradation voltage; a second switching element including afirst end electrically coupled to the second end of the first switchingelement, and a second end; a pixel circuit including a light-emittingelement and a transistor; and a data line electrically coupled to thepixel circuit, wherein the transistor supplies a current to thelight-emitting element according to the gradation voltage supplied viathe data line, and the first capacitor is disposed to overlap thetransistor in plan view.
 2. The light-emitting device according to claim1, wherein the transistor is provided in a circuit layer, thelight-emitting device comprises: a first wiring layer including a firstwiring disposed along the data line; and a first metal layer disposedbetween the circuit layer and the first wiring layer and supplied with afixed potential, and the first metal layer includes a portion disposedbetween the data line and the first wiring.
 3. The light-emitting deviceaccording to claim 2, wherein the first metal layer overlaps thetransistor in plan view.
 4. The light-emitting device according to claim3, wherein the first capacitor is provided between the first wiring andthe first metal layer.
 5. The light-emitting device according to claim2, comprising: a second metal layer disposed between the circuit layerand the first metal layer and supplied with a fixed potential; and asecond wiring layer disposed between the first metal layer and thesecond metal layer and provided with the data line.
 6. Thelight-emitting device according to claim 5, wherein the second metallayer overlaps the transistor in plan view.
 7. The light-emitting deviceaccording to claim 5, comprising a plurality of wiring portionsconfigured to couple the first metal layer to the second metal layer,wherein the data line includes a portion disposed between a pair ofwiring portions of the plurality of wiring portions.
 8. Thelight-emitting device according to claim 2, comprising: a fixedpotential line disposed along the data line and supplied with a fixedpotential; and a second capacitor being a capacitor between the firstwiring and the fixed potential line and configured to hold the datasignal.
 9. The light-emitting device according to claim 8, wherein thefirst wiring and the fixed potential line are provided in the samelayer.
 10. The light-emitting device according to claim 2, wherein thedata line is disposed between the transistor and the first wiring.
 11. Alight-emitting device comprising: a data signal supply circuit; a firstswitching element including a first end electrically coupled to the datasignal supply circuit, and a second end; a first capacitor electricallycoupled to the second end of the first switching element; a secondswitching element including a first end electrically coupled to thesecond end of the first switching element, and a second end; a secondcapacitor including a first end electrically coupled to the second endof the second switching element, and a second end; a pixel circuitincluding a light-emitting element and a transistor; and a data lineelectrically coupled to the second end of the second capacitor and thepixel circuit, wherein the first capacitor is disposed to overlap thetransistor in plan view.
 12. A light-emitting device comprising: a datasignal supply circuit; a first switching element including a first endelectrically coupled to the data signal supply circuit, and a secondend; a first capacitor electrically coupled to the second end of thefirst switching element; a second switching element including a firstend electrically coupled to the second end of the first switchingelement, and a second end; a pixel circuit including a light-emittingelement and a transistor; and a data line electrically coupled to thesecond end of the second switching element and the pixel circuit,wherein the first capacitor is disposed to overlap the transistor inplan view.
 13. An electronic apparatus comprising the light-emittingdevice according to claim
 1. 14. An electronic apparatus comprising thelight-emitting device according to claim
 11. 15. An electronic apparatuscomprising the light-emitting device according to claim 12.